The present invention pertains to a tie that is useful for forming a loop for retaining a bundle of elongated articles, such as cables. Such a tie is commonly known as a cable tie.
One type of tie includes an elongated tongue with two ends and two broad sides, a locking head at one end of the tongue, a tip at the other end of the tongue, a first set of ratchet teeth extending along one broad side of the tongue and a second set of ratchet teeth extending along the other broad side of the tongue, wherein the locking head has sides defining an opening for receiving the tip of the tongue, the sides including a movable pawl that is hinged at one side of the opening and an abutment surface that is across the opening from the pawl, wherein the pawl has at least one pawl tooth disposed for engaging the first set of ratchet teeth when the tip of the tongue has been inserted through the opening with the first set of ratchet teeth facing the pawl, wherein the pawl, when the at least one pawl tooth is so engaged, is movable toward the abutment surface in response to pressure applied to the tongue in a direction opposite to the direction of insertion in order to force the second set of ratchet teeth against the abutment surface; and wherein at least one tooth is disposed on the abutment surface for engaging the second set of ratchet teeth when the tip of the tongue has been inserted through the opening with the second set of ratchet teeth facing the abutment surface and the side of the tongue including the second set of ratchet teeth is forced against the abutment surface by movement of the pawl. Such a tie is described in U.S. Pat. No. 4,473,524 to Paradis.
In a tie described in published UK Patent Application No. GB 2 145 150 A, each of the pawl teeth has a locking surface extending toward an apex of the tooth at an angle the tongue has been inserted through the opening with the set of ratchet teeth facing the pawl; and wherein the side of the pawl including/he at least one tooth converges toward the opposite side of the pawl in said direction of insertion.
According to another aspect of the present invention, the tie comprises an elongated tongue with two ends and two broad sides, a locking head at one end of the tongue, a tip at the other end of the tongue and a set of ratchet teeth extending along one broad side of the tongue, wherein the locking head has sides defining an opening for receiving the tip of the tongue, the sides including a movable pawl within the locking head opening that is hinged at one side of said opening and an abutment surface that is across the opening from the pawl, wherein the pawl has at least one pawl tooth disposed for locking engagement with the set of ratchet teeth when the tip of the tongue has been inserted through said opening with the set of ratchet teeth facing the pawl, wherein at least one tooth of the set of ratchet teeth has a locking surface extending toward an apex of said tooth at an angle inclined away from said direction of insertion for locking engagement with the at least one pawl tooth when the tongue has been inserted through the opening with the set of ratchet teeth facing the pawl; and wherein the side of the pawl including the at least one tooth converges toward the opposite side of the pawl in said direction of insertion.
Both of the above aspects of the present invention are combined in the preferred embodiment.
Additional features of the present invention are described with reference to the detailed description of the preferred embodiments. inclined toward the direction of said insertion for locking engagement with a tooth of the set of ratchet teeth when the tongue has been inserted through the opening with the set of ratchet teeth facing the pawl; and each of the ratchet teeth on the one side of the tongue has a locking surface extending toward an apex of the tooth at an angle inclined away from the direction of insertion for locking engagement with a pawl tooth when the tongue has been inserted through the opening with the set of ratchet teeth facing the pawl. In such tie, the side of the pawl including the teeth diverges away from the opposite side of the pawl in the direction of insertion, whereby the tie is not readily removable from a mold when the tie is manufactured by injection molding.